The present invention relates generally to collapsible containers and more particularly to an improved latch for a collapsible container.
Collapsible containers are well known. Typically, four walls, each connected via a hinge to a base, are selectively moveable about the hinge between an upright use position in which the wall is generally perpendicular to the base and a collapsed position on the base. Various mechanisms have been provided to connect adjacent walls at the corners to selectively lock the container in the use position and selectively permit the collapse of the walls onto the base for transport or storage.
Generally, there are two kinds of collapsible containers. Some containers include latches at the corners that lock the walls in the upright position until the latch is selectively actuated to permit the movement of the walls to the collapsed position. Typically these latches are actuated manually by a user selectively deflecting the latch to permit movement of the walls. Other latches are optimized for actuation by automated equipment, which actuates the latch and collapses the container.
Another known type of collapsible container is the “knock-down” container. Often there is simply some sort of interference fit between a member on one wall with a complementary member on the adjacent wall. Thus, no actuation of a latch is required. The walls are forcibly moved into the upright position and can be forcibly knocked-down to the collapsed position without actuation of any latches. One disadvantage of the knock-down container is that the force required to lock the walls in the upright position may be much higher than normal latched containers because this is the same (or nearly the same) force that retains the walls in the upright position. In fact, knock-down containers often require the user to manually force the interference members together one-by-one.
U.S. Pat. No. 7,017,766, the assignee of which is the assignee of the present invention, provides a collapsible container for which the force required to move the walls to the upright position is as low as a typical latched collapsible container. The walls are also easily collapsed by actuating the latch mechanism but can also be knocked-down forcibly without actuating the latches. The collapsible container in that patent provides a latch protruding laterally from a first wall and engaging an adjacent second wall to retain the walls in an upright position. The latch is deflectable in a direction generally parallel to the plane of the first wall to selectively disengage the latch from the second wall. The latch and the second wall include complementary first ramped surfaces that engage one another to deflect the latch downwardly as the adjacent wall is raised to the upright position. The latch and the adjacent wall further both include second ramped surfaces that engage one another when the adjacent wall is in the upright position. The second ramp surfaces are much steeper than the first ramped surfaces, such that the force required to deflect the latch while moving the adjacent wall to the collapsed position is much greater than the force necessary to deflect the latch while moving the adjacent wall to the upright position.
Thus, the second wall in that patent can be moved to the collapsed position either by manually actuating the latch and applying a light force, or by knocking down the adjacent wall with a higher force causing the engagement of the second ramped surfaces on the second wall and latch thereby causing the latch to deflect and release the second wall.
The prior design works well in most instances; however, at times the latches require a knockdown force greater than would be desirable to disengage the latches.